Well Water in Orange County: What to Test and Why

High Risk
Testing Strongly Recommended 10475 samples analyzed
Top Concerns in This County
Radon Pfoa Chloride

Why This Happens Here

Groundwater in Orange County contains radon, chloride, and PFOA that well owners need to know about. Chloride, lead, PFOA, PFOS, and radon all exceed EPA health standards in this county, making these serious concerns.

Radon seeps naturally from the carbonate rock beneath Orange County. Chloride enters groundwater from road salt spread on highways and local roads, especially near treated surfaces. PFOA comes from industrial use and manufacturing--it persists in the environment and moves into groundwater over time.

Groundwater in this county is moderately hard, driven by calcium and magnesium released from the carbonate rock. Slightly acidic rainwater dissolves these minerals as it moves through limestone and similar stone below the surface. Most wells in Orange County show moderate mineral levels, though individual wells vary based on depth and location.

What This Means for You

Wells in Orange County commonly exceed EPA health standards for chloride, lead, PFOA, PFOS, and radon. Lead can harm children's brain development and damage kidneys in people of all ages. Radon is a radioactive gas that increases lung cancer risk when breathed over time. PFOA and PFOS are human-made chemicals linked to serious health effects. Chloride at high levels can affect people with certain health conditions.

Moderate iron in county wells can create reddish-brown staining on fixtures and laundry. You may notice a metallic taste in the water. Iron can also cause buildup inside pipes and appliances over time.

We recommend a comprehensive water test for metals, minerals, and radon since multiple contaminants exceed health standards in this county. Testing is the only way to know what is actually in your well so it can be properly treated. Every well is different--yours could have higher or lower levels than what is common here. A comprehensive panel typically costs $200-400. Treatment options like activated carbon filters and aeration systems can address these specific contaminants.

Not sure if your well is affected? Get certified results in 5–7 days.

Test Your Well Water with Tap Score →

Contaminant Detection Data

Contaminant Samples % Above MCL Distribution Confidence Risk
Radon 27 37% 44% · 18% · 37% Moderate High
Chloride 124 25% 68% · 6% · 25% High High
PFOA ⓘ municipal 118 11% 87% · 2% · 11% High Moderate
PFOS ⓘ municipal 118 3% 97% · 0% · 3% High Moderate
Elevated concentration, not % above limit
Lead 63 2% 94% · 5% · 2% Moderate Low
Sulfate 69 0% 94% · 6% · 0% Moderate Low
Fluoride 5 0% 100% · 0% · 0% Low Low
Iron 9 0% 89% · 11% · 0% Low Low
Uranium 12 0% 100% · 0% · 0% Low Low
PFNA ⓘ municipal 118 0% 100% · 0% · 0% High Safe
HFPO-DA (GenX) ⓘ municipal 118 0% 100% · 0% · 0% High Safe
PFHxS ⓘ municipal 118 0% 100% · 0% · 0% High Low
Sodium 94 Moderate Low
Manganese 1 0% 100% · 0% · 0% Low Safe
Nitrate 1 0% 100% · 0% · 0% Low Safe
Nitrite 1 0% 100% · 0% · 0% Low Safe
Arsenic 1 0% 100% · 0% · 0% Low Safe
Hardness 1 Low Safe
Fecal Coliform 1 0% 100% · 0% · 0% Low Safe
Total Coliform 1 0% 100% · 0% · 0% Low Safe
E. coli 1 0% 100% · 0% · 0% Low Safe
PFBS ⓘ municipal 118 100% · 0% · 0% High Low
pH 17 Moderate Low

MCL = Maximum Contaminant Level (EPA limit for public water; used as benchmark for private wells). Distribution shows % of sampled wells in each concentration band. Methodology.

Data shows potential risk — a certified test confirms whether your water is affected.

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Population Health Context

Population-level CDC data. Not individual risk prediction.

6.0%
Heart Disease Rate
(state avg: 6.4%)
6.3%
Cancer Prevalence
(state avg: 6.7%)

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